1. Field of the Invention
The present invention relates to a solid organometallic compound-filled container and a filling method thereof. More specifically, the present invention relates to a solid organometallic compound-filled container and a filling method thereof capable of stably supplying an apparatus for vapor phase epitaxial growth with a constant concentration of a solid organometallic compound over a long term. This solid organometallic compound is a material for use in a vapor phase epitaxial growth technique based on Metalorganic Chemical Vapor Deposition (hereinafter, abbreviated as “MOCVD”) method or the like which is used in the manufacture of electronics materials such as compound semiconductors.
2. Description of the Related Art
Organometallic compounds have broad use as materials in manufacture of electronics materials.
In the manufacture of electronics material using organometallic compounds, vapor phase epitaxial growth based on the MOCVD method or the like has often been used in recent years. For example, a thin film of compound semiconductor is manufactured by the MOCVD method using an organometallic compound such as trimethylaluminum, trimethylgallium, and trimethylindium as a material.
When such an organometallic compound is used in the MOCVD method and the organometallic compound is solid in the condition of the MOCVD method, usually, a filled container A having a carrier gas inlet (2a) and a carrier gas outlet (3a) as shown in FIG. 34 is filled with the organometallic compound, a carrier gas such as hydrogen gas is introduced into the container via the carrier gas inlet (2a), and the organometallic compound is drawn out as a gas in which the organometallic compound is saturated in the carrier gas via the carrier gas outlet (3a) to be supplied to the MOCVD apparatus.
When the organometallic compound is solid at the temperature that is used in the supplying step, a flow channel is formed in the filled container A where the carrier gas passes through without sufficiently contacting with the solid organometallic compound, making it difficult to keep the carrier gas and the solid organometallic compound in contact with each other in a uniform condition. Therefore, it is difficult to stably supply the MOCVD apparatus with the solid organometallic compound from the filled container A at a constant concentration over a long term. When the solid organometallic compound is supplied according to the aforementioned method using the carrier gas, the ratio of the amount of solid organometallic compound that can be stably supplied to the MOCVD apparatus relative to the filling amount of solid organometallic compound decreases, as the amount of solid organometallic compound to fill the filled container A increases, so that the amount of the solid organometallic compound remaining in the filled container increases, and effective use of the solid organometallic compound is disabled.
For solving these problems, various proposals have been made concerning the method of filling the filled container A with the solid organometallic compound. For example, a method of filling a filled container with a solid organometallic compound together with a filling material is proposed in Japanese Patent Publication No. Hei 5-39915, Japanese Patent Publication No. Hei 6-20051, Japanese Patent Laid-Open Publication No. Hei 7-58023, Japanese Patent Laid-Open Publication No. Hei 8-250440, Japanese Patent Laid-Open Publication No. Hei 8-299778, and the like. For example, a method of filling a filled container A with an inert carrier covered with a solid organometallic compound is proposed in Published Japanese Patent No. 2651530 and the like.
In addition to these proposals, various proposals concerning structure of a filled container itself to be filled with a solid organometallic compound have been made to solve the above-mentioned problems. For example, a filled container B having a diffuser (20a) for uniformizing gas disposed at the carrier gas inlet as shown in FIG. 35 to allow the carrier gas to uniformly flow with respect to the solid organometallic compound is proposed in Japanese Patent Publication No. Hei 2-124796 and the like.
Furthermore, a filled container C having a solid organometallic compound chamber (21a) having air permeability as shown in FIG. 36 is proposed, for example, in Japanese Patent Laid-Open Publication No. Hei 10-223540 and the like.
Furthermore, a filled container (hereinafter referred to as filled container D) in which a porous inlet chamber as shown in FIG. 37 serves as a filled region for solid organometallic compound is proposed, for example, in Japanese Patent Laid-Open Publication No. 2002-83777 and the like.
As shown in FIG. 34, the conventional filled container A has a carrier gas inlet (2a) and a carrier gas outlet (3a) in a single container, and has a flow channel (8a) implemented by a dip tube with a lower opening (7a) which extends from the lower part of the carrier gas outlet to the bottom of the filled container A within the filled container. The present inventor carried out examination to find that when the filled container A having the structure as shown in FIG. 34 was used, in supplying a solid organometallic compound to the MOCVD apparatus using the carrier gas, the longer the supply period of the organometallic compound by the carrier gas, the more the supply amount of the organometallic compound in the carrier gas decreased in a gradual manner. In particular, the effect of stably supplying the solid organometallic compound was significantly impaired when the filling amount of the solid organometallic compound was increased, or the flow rate of the carrier gas was increased. Therefore, the filled container A does not achieve sufficient effect to stably supply the MOCVD apparatus with the solid organometallic compound over a long term.
Also, various filled containers that have been proposed other than that shown in FIG. 34 have a problem in that they are still not satisfactory in stably supplying the MOCVD apparatus with the solid organometallic compound over a long term in the method using carrier gas, or that the outer size of the filled container is significantly large.
As described above, the conventional filled containers for solid organometallic compound are faced with various problems, and there is a need for improving the supply stability of the solid organometallic compound and preventing the filled container from having a significantly large outer size.